Chika Takami is the primary protagonist and the founder and leader of the school idol group Aqours. She is a second-year student at Uranohoshi Girls' High School, a small rural school located in the town of Numazu. Chika is the youngest of three sisters, and her family owns and operates a traditional Japanese inn known as a ryokan, which features open-air hot springs with an ocean view. She lives in this inn with her parents, her two elder sisters named Shima and Mito, and the family's large pet dog, Shiitake. As a child, she was close friends with You Watanabe and Kanan Matsuura, having grown up alongside them in the same coastal town.

Chika's personality is defined by her immense energy, sociable nature, and a powerful sense of perseverance. She is fundamentally optimistic and possesses a positive, can-do attitude that gradually inspires and influences the people around her to take action. Despite this cheerful exterior, she has a more sensitive side that she often conceals. Chika tends to hide her frustration and sadness, trying not to cry in front of others because she worries that showing her own distress might lower the morale of her friends and groupmates. While she is endlessly encouraging, she can become visibly upset when conflicts arise between her friends, as she deeply cherishes the bonds of friendship and dislikes what she sees as petty confrontations. In such situations, she is not afraid to step in and mediate. She is also known for her somewhat goofy and impulsive nature, and she is not particularly academically gifted, often struggling with schoolwork. At the start of the series, Chika views herself as an ordinary and unremarkable person, especially when comparing herself to her more talented childhood friends. This feeling of being a "normal" person is a core part of her identity.

The central motivation for Chika is her desire to find her own "shine" and move beyond her perceived ordinariness. This drive is ignited after she sees a performance by the legendary school idol group µ's during a trip to Tokyo. Fascinated and deeply inspired by their ability to shine brightly despite being school idols, she resolves to start her own school idol club at Uranohoshi Girls' High School. Her initial goal is simply to emulate µ's, but her purpose evolves into a mission to save her beloved school from closure due to a lack of new applicants, mirroring the success of the group that inspired her. Later, after a devastating failure, her goal shifts from grand victory to a more personal one: to transform zero into one, achieving a single small success that can serve as a foundation for greater things.

In the story, Chika acts as the driving force behind the formation of Aqours, taking on the crucial role of bringing together nine girls from different years and with diverse personalities. Her primary role is that of a leader who pushes from behind, supporting each member personally and noticing when her friends are struggling. She is not a leader who always knows the right path but one who learns and grows alongside her group. Her key relationships include her childhood friend You Watanabe, who is her first and most steadfast supporter. She also forms a strong bond with Riko Sakurauchi, a transfer student who moves into the house next door to her family's inn. Early on, she frequently clashes with the student council president, Dia Kurosawa, who opposes the formation of an idol club, but she eventually wins her over with her persistence.

Throughout the series, Chika undergoes significant development. A pivotal moment occurs when Aqours performs in Tokyo and receives zero votes in a competition, a crushing defeat that forces Chika to confront her own limitations and the fact that simply imitating µ's will not lead to success. This failure leads to a crucial epiphany: instead of trying to follow in the footsteps of her heroes, she must find her own unique path and lead Aqours to discover their own individual forms of radiance. Her determination is further tested when she insists on mastering a nearly impossible dance move, known as the "Miracle Wave," pushing herself to the point of injury in her relentless pursuit of growth for the group. The emotional climax of her journey comes when, despite Aqours winning the Love Live! competition, they are unable to save their school from closing. Chika is initially devastated, but she ultimately learns that the true "shine" she was searching for was not victory or fame, but the precious, irreplaceable moments she spent with her friends working toward their shared dream. In terms of abilities, beyond her leadership and interpersonal skills, Chika is noted to be talented in specific physical activities including the horizontal bar, table tennis, calligraphy, and she also enjoys softball and going to karaoke.